I. Field of the Disclosure
The technology of the disclosure relates generally to electronic devices configured to communicate on a communications bus, and more particularly to electronic devices configured to communicate their identification information over the communications bus as part of a defined communications protocol to avoid bus collisions.
II. Background
Electronic devices, such as mobile phones and computer tablets as non-limiting examples, have proliferated throughout society supporting a myriad of uses. These electronic devices commonly include a microphone and speakers. Common microphones and speakers used in electronic devices have analog interfaces, requiring dedicated two (2) port wiring to connect each device. However, electronic devices are commonly starting to include multiple audio devices, such as multiple microphones and speakers. Thus, it may be desired to allow for a microprocessor or other control device in such electronic devices to be able to communicate audio data to multiple audio devices over a common communications bus. In this regard, it may also be desired to provide a defined communications protocol for transporting digital data relating to audio channels to different audio devices in an electronic device over the communications bus.
In this regard, FIG. 1 is a block diagram of an exemplary system 10 having one (1) master device 12 and four (4) slave devices 14(1)-14(4) communicatively coupled to a common communications bus 16 as electronic devices. The master device 12 communicates with the slave devices 14(1)-14(4) over the communications bus 16. Thus, in the system 10, a time division multiplexed (TDM) frame structure is used for transport of bitrate media streams over the communications bus 16 to avoid data collisions. The master device 12 allocates a transmission time slot to each of the slave devices 14(1)-14(4) for bus communications. Thus, the protocol requires that each of the slave devices 14(1)-14(4) is connected to the communications bus 16 be identified by the master device 12 through a device identification, also called a “Device_Id.” For example, the Device_Id may have a specified bit length in the protocol, such as five (5) bits, for example. Identifying different Device_Ids of the slave devices 14(1)-14(4) allows the master device 12 to allocate different transmission time slots to each of the slave devices 14(1)-14(4) to avoid data collisions on the communications bus 16.
A Device_Id would be loaded into an electronic device by a manufacturer as a default device identification to be used to identify the electronic device. For example, as shown in FIG. 1, a Device_Id 26(1) can be loaded into the master device 12. Device_Ids 28(1)-28(4) can be loaded into the respective slave devices 14(1)-14(4). However, it is possible that the same Device_Id 28 could be loaded into different slave devices 14(1)-14(4). In this case, the slave devices 14(1)-14(4) having the same Device_Id 28 would be identified by the master device 12 with the same Device_Id 28 causing data collisions on the communications bus 16. One way to ensure that each slave device 14(1)-14(4) has a unique Device_Id 28(1)-28(4) is to ensure that each slave device 14(1)-14(4) is loaded with a unique Device_Id during production. Multiple slave devices manufactured by the same manufacturer may have the same device identification. Providing unique Device_Ids 28 would require a larger device identification storage facility, which may prohibitively increase costs of an otherwise low-cost device. Further, even if the slave devices 14(1)-14(4) are manufactured by different manufacturers, it may be difficult or not possible to guarantee that each manufacturer will employ unique device identification in their slave devices.
It is therefore desirable to provide unique device identifications for electronic devices provided in a communications system employing a common communications bus to allow unique identification of the slave electronic devices to avoid data collisions in a cost effective manner.